How to remove properties from an object array?

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I am trying to remove a property from an object array.

export class class1 {
  prop1: string;
  prop2: string;
  prop3: string;
}
export class class2 {
  myprop = [
    { prop1:'A', prop2:"1", prop3:"descr1" },
    { prop1:'B', prop2:"2", prop3:"descr2" },
    { prop1:'C', prop2:"3", prop3:"descr3" },
  ];
  get(): class1[] {
    return this.myprop ;
  }
  add(value: class1): void {
    this.myprop.push(value);
  }
}
var var1 = class2.get();
var var2 = 

I would like var2 contain something like this.

  [
    { prop1:'A', prop3:"descr1" },
    { prop1:'B', prop3:"descr2" },
    { prop1:'C', prop3:"descr3" },
  ];

Is there a way to convert/cast var1 into the above? In other words, I would like to remove prop2 from var1 object array and assign it to var2. How can I do that?

You can delete object property like this e.g.

    var myprop = [
        {prop1: 'A', prop2: "1", prop3: "descr1"},
        {prop1: 'B', prop2: "2", prop3: "descr2"},
        {prop1: 'C', prop2: "3", prop3: "descr3"},
    ];

    myprop = myprop.filter(function (props) {
        delete props.prop2;
        return true;
    });
    console.log(myprop);

How to remove a property from a JavaScript object, The semantically correct way to remove a property from an object is to use the delete keyword. Given the object. const car = { color: 'blue',  The delete operator deletes both the value of the property and the property itself. After deletion, the property cannot be used before it is added back again. The delete operator is designed to be used on object properties. It has no effect on variables or functions.

This seems like a great time to use .map()

var var1 = class2.get();
var var2 = var1.map(obj => ({prop1: obj.prop1, prop3: obj.prop3}));

Short, sweet, and does what you want.

MDN docs for .map()

How To Remove a Property from a JavaScript Object, After deletion, the property cannot be used before it is added back again. The delete operator is designed to be used on object properties. It has no effect on  Announcement -> I am creating video tutorials of this website tutorials/articles/guides and publishing on my youtube channel at Java Guides - YouTube Channel.Subscribe to my youtube channel for daily useful videos updates.

Casting in TypeScript won't remove the property but only hide it in your IDE because it will be compile to JavaScript for runtime.

First of all, if you don't want to remove prop2 from var1 while deleting the property from var2 you need to clone it. For that you will need this JavaScript function:

function cloneObject(obj) {
    if (obj === null || typeof obj !== 'object') {
        return obj;
    }

    var temp = obj.constructor(); // give temp the original obj's constructor
    for (var key in obj) {
        temp[key] = cloneObject(obj[key]);
    }

    return temp;
}

Use the clone function to clone var1 and loop each object in var2 to remove property prop2. You can do so with JavaScript by combining array.forEach and delete:

var var2 = cloneObject(var1);
var2.forEach((obj) => { delete obj.prop2; });

Doing so will KEEP prop2 in var1 but REMOVE it from var2

9 Ways To Remove 🗑️ Elements From A JavaScript Array [Examples], Removing & Clearing Items From JavaScript arrays can be confusing. to remove properties from JavaScript objects, which arrays are objects. Javascript delete is an inbuilt operator that removes property from object. The delete operator removes both the value of the property and the property itself. If there are no more references to the same property, then it is eventually released automatically.

// Use delete:

    var user = {
      firstname:"Jack",
      lastname:"Prince",
    };

    var result = delete user.firstname;
    console.log(result,"firstname deleted");
    console.log(user);
    
    
    
  //using Object rest spread operator 

   const { firstname, ...data } = user;
   console.log(data);
  

delete operator, The JavaScript delete operator removes a property from an object; if no Array , Object and properties that are created as non-configurable  If you know the value you want to remove from an array you can use the splice method. First you must identify the index of the target item. You then use the index as the start element and remove just one element.

How to remove an element from Array in JavaScript?, The delete operator is designed to remove properties from JavaScript objects, which arrays are objects. Remove element using delete operator. The delete operator is used to remove properties from objects. const obj = { foo: "bar" } delete obj.foo obj.hasOwnProperty("foo") // false Note that, for arrays, this is not the same as removing an element. To remove an element from an array, use Array#splice or Array#pop.

How to remove object from array of objects using JavaScript , forEach() method to traverse every object of the array. For each object use delete obj.property to delete the certain object element from array of objects. Example:  Remove a PowerShell Object property 2017/06/14 | less than 1 minute read | Someone at work was recently asking me about the following: How to remove a property from a PowerShell Object ? Here is how you can achieve that. Create a PowerShell Object

Remove blank attributes from a JavaScript Object, Given a JavaScript Object with null values in it, the task is to remove those null values from the object using javascript. JavaScript | Remove blank attributes from an Object. How to remove object from array of objects using JavaScript ? It is not possible to directly unset a property that has an integer key. e.g. $o=(object)array('a','b','c');(You have to convert the object (back) to an array even to simply accesssuch properties!)– danortonMar 19 '14 at 22:09. 4.

Comments
  • That’s not where you would use filter. You’d use filter to remove or keep items in an array, not properties. delete, here, creates side-effects. This answer is using filter in a completely unsemantic way as a general-purpose iteration method.
  • Perfect, thanks! Sometimes the good old JS (or at least its newer versions) is so much more readable then lodash or other libs..
  • Maybe even shorter :D var1.map( ({ prop1, prop2 }) => ({ prop1, prop2 }) );